Method of making bags



June 18, 1963 A. N. WEEKS METHOD OF MAKING BAGS 2 Sheets-Sheet 1 FiledFeb. 15, 1961 v June 18, 1963 A. N. WEEKS METHOD OF MAKING BAGS 2Sheets-Sheet 2 Filed Feb. 15, 1961 i y 11 a r 1; s7, t; h 2 AJIW MN m%United States Patent Ofi souri Filed Feb. 13, 1961, Ser. No. 88,963Claims. (Cl. 11210) This invention relates to methods of makingmulti-wall paper bags having a tubular sheet plastic liner.

Among the several objects of this invention may be. noted the provisionof methods of economically manrufactoring in quantity production sewnmulti-wall paper bags having a liner which consists of a separate tubeof sheet plastic material, the liner being hermetically heatsealed atthe bottom of the bag to prevent ingress of. :3 moisture and the bagalso being sewn at the bottom to provide a strong bottom closure withoutthe hermetic seal. Other objects and features W111 be in part apparentand in part pointed out hereinafter.

The invention accordingly comprises the methods here-, inafterdescribed, the scope of the invention being indicated in the followingclaims.

'In the accompanying drawings, in which several of various possibleembodiments of the invention are illustrated,

FIG. 1 is a perspective view illustrating a first step in themanufacture of bags according to invention;

FIG. 2 is a plan view illustrating concluding steps of a first method ofthis invention for making .a first type of bag;

'FIG. 3 is a perspective view illustrating a bag made by i the methodillustrated in FIGS. 1 and 2;

FIG. 4 is a cross section taken on line 44 of FIG. 3, thicknesses beingexaggerated;

FIG. 5 is a cross section takenon line 55 of FIG. 3, y

thicknesses being exaggerated and parts being broken away to reduce theheight of the view.

Corresponding reference characters indicate corresponding partsthroughout the drawing.

Referring to the drawings, FIG. 1 illustrates a first step common to themethods of this invention for making multi-wall paper bags having atubular sheet plastic liner. As shown therein, flexible heat-scalablesheet plastic tubing 1 (polyethylene tubing, for example) is drawn froma supply roll 3 and provided with transverse heat seals 5 spaced at baglength intervals along the tube. Transverse lines of perforations 7 aremade in the tubing (through both walls of the tubing), these lines beingspaced at bag length intervals, and spaced from but ad acent to thetransverse heat seals. The spacing between each line of perforations andthe adjacent heat seal is only a short distance, such as, for example,one inch.

A paper web 1 1 (which may be a multi-ply paper web, although shown inthe drawings as a single web for simplicity) is then formed into a tube13 around the plastic tubing with the longitudinal edges of the paperweb lapped and adhered together as indicated at 15. The formation of thepaper web into a tube around the plastic tubing is carried out by meansof a suitable conventional tuber, such as is well known in the art,while the plastic tubing and the paper web are fed in the directionindicated by the arrow in FIG. 2. As shown in FIG. 2, web 11 is providedwith transverse lines of perforations 17 3,094,083 Patented June 18,1963 ice spaced at bag length intervals before the web is formed intotube 13 around the plastic tubing.

The paper web and the plastic tubing are fed at the same rate of speedand, when the web is formed into tube 13 around the plastic tubing, thelines of perforations 17 in the web are brought substantially intoregistration with the lines of perforations 7 in the plastic tubing.

The resulting composite paper and plastic tubing is then segmented intoindividual bag lengths by snapping off the latter at the end of thetubing on the registering lines of perforations 7 and 17. It will beunderstood that instead of initially providing perforations in theplastic tubing and paper web, the composite paper and plastic tubingcould be segmented into individual bag lengths by cutting off theindividual bag lengths a short distance from each heat seal with aconventional cutter. Each bag length comprises a plastic liner 1a withina paper tube 13a, with a transverse heat seal 5 across the plastic:liner adjacent one end of the bag length. Each bag length is then sewnacross the width thereof on a line 19 between the heat seal 5 and theadjacent end of the bag.

As a result of the above described operations, a bag B (see FIGS. 3-5)is formed comprising an outer paper tube 13a (which may be a multi-plypaper tube) and a tubular sheet plastic liner 1a within the outer papertube 13a. The liner is hermetically sealed at heat seal 5 adjacent oneend of the bag to prevent ingress of moisture, and the bag has the sewnbottom seam 19 between the heat seal and the bottom of the bag toprovide a strong bottom closure, with the needle holes made in sewingseam 19 below the seal 5 so that the hermetic seal is not affected.

The bag may be closed at the top after filling in various ways, such as,for example, bunching the top of the bag and tightly wire-tying, orproviding a sewn top closure with a sealing tape over the sewing, or, iffeasible for the type of paper used, heat-sealing and then sewing abovethe heat seal. When extensible paper is used, the paper may be foldeddown to expose the upper end of the plastic liner, which may then beheat-sealed, after which the paper may be brought back up and sewn.

FIG. 6 illustrates an alternative method of making paper bags with atubular sheet plastic liner extending above the top of the outer papertube. According to this method, flexible heat-scalable sheet plastictubing 21 is provided with transverse heat seals 25 and transverse linesof perforations 27 adjacent the heat seals in essentially the samemanner as shown in FIG. 1. However, each line of perforation and theadjacent heat seal may go more closely spaced than in the tubing shownin A paper web 81 is then formed into a tube 33 around the plastictubing and the longitudinal edges of the paper web are overlapped andadhered together as indicated at 35 in conventional manner. The web isprovided with transverse lines of perforations 37 spaced at intervalscorresponding to the spacing of lines oi perforations 27. The Web 31 isformed into tube 33 around the plastic tubing 25 with the lines ofperforations 37 offset from the lines of perforations 27 in the plastictubing, and on the opposite side of lines 27 from the heat seals 25.

The resultant composite paper and plastic tubing is then segmented intoindividual bag lengths by snapping off the latter at the end of thetubing on the lines of perforations 27 and 37. Each bag length comprisesa plastic liner 2111 having a cuff 39 extending outwardly from one endof paper tube 33a which surrounds the liner, with a transverse heat seal25 across the plastic liner adjacent the other end of the tube 33a andspaced inward therefrom. Each bag length is then sewn acres the widththereof on a line 41 between the heat-sealed end 3 of the plastic linerand the adjacent end of the paper tube 33a.

As a result of the above described operations with respect to FIG. 7, abag B1 (see FIGS. 7 and 8) is formed comprising an outer paper tube 33a(which may be a multiply tube) and a tubular sheet plastic liner 21awithin the outer paper ply with the cuff 39 of the liner extendingoutward frornthe paper ply at the open end of the bag. The liner of thebag B1 is hermetically sealed at heat seal 25 adjacent one end of theliner to prevent ingress of moisture, and the bag has the sewn bottomseam 41 between the end of the liner adjacent the heat seal and the endof the bag to provide a strong bottom closure, with the needle holes insewing seam 41 below the liner and heat seal so that the hermetic sealis not affected. The cuff extending above the paper ply may beconveniently heat sealed for closing of the bag, then folded down intothe bag for sewing of a top closure.

In view of the above, it will be seen that the several objects of theinvention are achieved and other advantageous results attained.

As various changes could be made in the above methods without departingfrom the scope of the invention, it is intended that all mattercontained in the above description or shown in the accompanying drawingsshall be interpreted as illustrative and not ina limiting sense.

I claim:

l. The method of manufacturing paper bags with 7 verse heat seals andlocatedat intervals along the length of said composite tubing, wherebyeach bag length comprises a plastic liner within a paper tube with atransverse heat seal across the plastic liner spaced from and adjacent 1one end of the bag length, and stitching each bag length across thewidth thereof along a line between said one end of the bag length andsaid heat seal.

2. The method of manufacturing paper bags with 4 thereof along a linebetween said one end of the bag length and said heat seal.

3. The method of manufacturing paper bags with plastic liners comprisingproviding a length of heat-sealable plastic tub-ing with transverseseals spaced at bag length intervals and perforations on transverselines spaced from but adjacent to the heat seals, forming a paper Webhaving perforations on transverse lines spaced at bag length intervalsinto a tube around the plastic tubing, each line of perforations in thepaper web being substantially in register with a line of perforations inthe plastic tubing, segmenting the resultant composite tubing intoindividual bag lengths on the substantially registered lines ofperforations, whereby each bag length comprises a plastic liner within apaper tube, the liner extending from one end of the paper tube to theother and having a trans verse heat seal spaced from and adjacent oneend of the bag length, and stitching each bag length across the widththereof along a line between said one end of the bag length and saidheat seal.

4. The method of manufacturing bags with plastic liners comprisingproviding a length of heat-scalable plastic tubing with transverse heatseals spaced at equal intervals and with perforations on transverselines adjacent the heat seals, forming a paper web having perforationson transverse lines spaced at said intervals into a tube around theplastic tubing, each line of perforations in the paper webbeinglongitudinally spaced from a line of perforations in the plastic tubing,segmenting the resultant composite tubing into individual bag lengths onthe transverse lines of perforations, whereby each bag length comprisesa plastic liner within a paper tube, one end of the liner being spacedinward from one end of the paper tube and the liner projecting'fromtheother end of the paper tube, the liner having a transverse heat sealspaced from and adjacent said one end of the paper tube, and

stitching each bag length across the width thereof along a line betweensaid oneend of the paper tube and said heat seal.

5. The methof of claim 4 wherein each bag length is stitched on a linebetween said one end of the paper tube and the adjacent inwardly spacedend of the liner.

plastic liners comprising providing a length of heat-seal able plastictubing with transverse heat seals spaced at bag length intervals,forming a paper web into a tube around the plastic tubing, segmentingthe resultant tubing into individual bag lengths on transverse linesspaced from but adjacent to the transverse heat seals and located at baglength intervals along the length of said resultant tubing, whereby eachbag length comprises a plastic liner within a paper tube with atransverse heat seal across the plastic liner spaced from and adjacentone end of the bag length, and stitching each bag length across thewidth References Cited in the file of this patent UNITED STATES PATENTS2,095,910 "Bergstein Oct. 12, 1937 2,114,625 Bergstein Apr. 19, 19382,347,439 Shea et a1 Apr. 25, 1944 2,496,796 Kardon Feb. 7, 19502,737,860 Randall Mar. 13, 1956 2,751,140 Brady June 19, 1956 2,871,771Mercer Feb. 3, 1959 2,896,516 Tilton et al. July 28, 1959 2,898,027Scholle Aug. 4, 1959

1. THE METHOD OF MANUFACTURING PAPER BAGS WITH PLASTIC LINERS COMPRISINGPROVIDING A LENGTH OF HEAT-SEAL ABLE PLASTIC TUBING WITH TRANSVERSE HEATSEAL SPACED AT INTERVALS ALONG THE LENGTH OF THE TUBING, FORMING A PAPERWEB INTO A TUBE AROUND THE PLASTIC TUBING, SEGMENTING THE RESULTANTCOMPOSITE TUBING INTO INDIVIDUAL BAG LENGTHS ON TRANSVERSE LINES SPACEDFROM BUT ADJACENT TO THE TRANSVERSE HEAT SEALS AND LOCATED AT INTERVALSALONG THE LENGTH OF SAID COMPOSITE TUBING, WHEREBY EACH BAG LENGTHCOMPRISES A PLASTIC LINER WITHIN A PAPER TUBE WITH A TRANSVERSE HEATSEAL ACROSS THE PLASTIC LINER SPACED FROM AND ADJACENT ONE END OF THEBAG LENGTH, AND STITCHING EACH BAG LENGTH ACROSS THE WIDTH THEREOF ALONGA LINE BETWEEN SAID ONE END OF THE BAG LENGTH AND SAID HEAT SEAL.